Modified Lattice of the Compact Storage Ring in the cSTART Project at Karlsruhe Institute of Technology

A very large acceptance compact storage ring (VLA-cSR) is under design at
the Institute for Beam Physics and Technology (IBPT) of the Karlsruhe
Institute of Technology (KIT, Germany). The combination of a compact
storage ring and a laser wakefield accelerator (LWFA) might be the basis for
future compact light sources and advancing user facilities. Meanwhile, the
post-LWFA beam should be adapted for storage and accumulation in a
dedicated storage ring. Modified geometry and lattice of a VLA-cSR operating
at 50 MeV energy range have been studied in detailed simulations. The main
features of a new model are described here. The new design, based on 45°
bending magnets, is suitable to store the post-LWFA beam with a wide
momentum spread (1% to 2%) as well as ultra-short electron bunches in the
fs range from the Ferninfrarot Linac- Und Test- Experiment (FLUTE). The DBAFDF
lattice with relaxed settings, split elements, and higher-order optics of
tolerable strength allows improving the dynamic aperture to an acceptable
level. This contribution discusses the lattice features in detail and different
possible operation schemes of a VLA-cSR.